In an interview with the Australian radio station 2DayFM, Valentine spilled the beans on who the best man for the wedding will be: Maroon 5 keyboardist Jesse Carmichael, who recently returned to the band after taking a hiatus.

"Those guys go back," he said. "What's interesting about the band is, I've been with the band for 15 years but I'm still one of the 'new' members!'"

Unlike him, Valentine said, Carmichael and Levine have known each other since they were 12 years old, so it's appropriate for him to get that honor.

However, Valentine will be a part of the ceremony.

"It's just another gig for me," he laughed to 2DayFM. "I'm gonna be playing some solo acoustic guitar during the ceremony when people are walking [in]."

He won't be playing Maroon 5 hits: Instead, Valentine said, he'll be serving up a "nice little medley" of Beatles tunes.

As for whether or not Levine and Prinsloo will "settle down" after they say their "I do's," Valentine laughed, "Oh no, not at all. They will not!" adding, "They're so much fun to be around together. I'm very happy for them."

Let's hope the happy couple gets to relax on their honeymoon -- if they take one -- since Levine has a busy fall planned: Maroon 5's new album, "V," is due in the beginning of September, and Levine is also prepping for the season premiere of "The Voice."